Random Vertices Getting Selected
I recently had the same problem. 

I followed steps noted here.

However, I instead changed the multisample settings from none to 2.
It seemed to help a bit, and then I changed it back and so far it seems to be working fine. 

Another forum suggest some have fixed the issue by disabling anti-aliasing in their GPU control panel.

So far it seems to be working as it should be.

I hope this helps.